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Water: Long Term 2 Enhanced Surface Water Treatment Rule

Long Term 2 Enhanced Surface Water Treatment Rule (LT2)

This site provides information about the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR or LT2 rule).

The purpose of the LT2 rule is to reduce illness linked with the contaminant Cryptosporidium and other disease-causing microorganisms in drinking water. The rule will supplement existing regulations by targeting additional Cryptosporidium treatment requirements to higher risk systems. This rule also contains provisions to reduce risks from uncovered finished water reservoirs and to ensure that systems maintain microbial protection when they take steps to decrease the formation of disinfection byproducts that result from chemical water treatment.

This web site is designed to provide you with information about the LT2 rule and links to additional information about particular topics such as training for implementation, answers to frequent questions and guidance. Use the links below or on the sidebar to find out more about the LT2 rule.


Basic Information - This page provides basic information about the rule.

LT2 Rule - Visit this page to read the LT2 rule and to learn about the history of the rulemaking.

LT2 Public Meetings - This page provides Federal Register Notices of Public Meetings, meeting summaries, and meeting presentations.

Compliance Help - If you need to comply with the LT2 rule, visit this page to get available guidance, tools and training information.

Lab Certification for Cryptosporidium - Visit this page to get information about EPA’s program to identify laboratories that can reliably measure the occurrence of Cryptosporidium in surface water using approved EPA methods.


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